Electrical apparatus and methods and apparatus for positioning and implanting components thereof

ABSTRACT

An anchor device is described that is adapted to support one or more conductors extending out of an opening in an outer surface of an eye, from a device implanted in the eye to a communications interface. The anchor device comprises a conductor receiving portion including a channel, the conductors being positionable through the channel; and a fixation portion connected to the conductor receiving portion, the fixation portion being adapted to be secured to the outer surface of the eye. The conductor receiving portion is configured to allow movement of the channel and/or conductors relative to the fixation portion. A visual prosthesis comprising the anchor device is also described, along with apparatus and methods for positioning the visual prosthesis or other types of implantable electrical apparatus.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority from Australian ProvisionalPatent Application No 2012903745 filed on 29 Aug. 2012, and U.S.Provisional Patent Application No. 61/694,447 filed on 29 Aug. 2012, thecontents of which are incorporated herein by reference.

FIELD

The present patent application relates to electrical apparatus andmethods and apparatus for positioning and implanting components of theelectrical apparatus.

BACKGROUND

Electrical apparatus that includes implantable components has beendeveloped for a variety of medical purposes. Commonly, the apparatuscomprises one or more electrodes that are implanted in or on a targetportion of a patient's body. The electrodes can electrically stimulatethe body and/or sense electrical activity in the body.

Electrical apparatus has been developed, for example, to restore orimprove vision within blind or partially blind patients. A visualprosthesis such as a retinal prosthesis commonly includes an implantablecomponent having an electrode array, situated on or in a substrate, forplacement in the eye on or near retinal nerve cells. Electrical signalsare transmitted via the electrodes to the retinal nerve cells,triggering a perception of light within the patient's brain. Theprosthesis can therefore provide the perception of vision to patients,e.g. whose retinal photoreceptors have become dysfunctional.

Commonly, a visual prosthesis is used in conjunction with a videocamera. A stream of images detected by the camera is converted intodigital signals by an image processor and electrical signals are appliedto the electrodes in accordance with the digital signals.

As another example, apparatus is being developed to diagnose, limit orprevent onset of epileptic seizures. Electrical activity is sensedand/or electrical stimulus is applied, by an implantable componenthaving one or more electrodes placed within or near the source orsources of seizures in the brain. The electrical stimulus is intended toterminate or at least counteract epileptic seizure events arising fromthose sources.

In both examples, to communicate with the electrodes when theimplantable component is located in a target position, a lead can extendfrom the implantable component and exit the body via an incision. Thelead can be connected to a communications interface such as a wirelesstransmitter/receiver, an electrical connector or an electrical plugsocket (e.g. a “pedestal”), located remotely from the implantablecomponent.

Any discussion of documents, acts, materials, devices, articles or thelike which has been included in the present specification is not to betaken as an admission that any or all of these matters form part of theprior art base or were common general knowledge in the field relevant tothe present disclosure as it existed before the priority date of eachclaim of this application.

SUMMARY

According to a first aspect, there is provided an anchor device adaptedto support one or more conductors extending out of an opening in anouter surface of an eye, from a device implanted in the eye to acommunications interface, the anchor device comprising:

a conductor receiving portion including a channel, the conductors beingpositionable through the channel; and

a fixation portion connected to the conductor receiving portion, thefixation portion adapted to be secured to the outer surface of the eye;

wherein the conductor receiving portion is configured to allow movementof the channel relative to the fixation portion.

According to a second aspect, there is provided an anchor device adaptedto support one or more conductors extending out of an opening in anouter surface of an eye, from a device implanted in the eye to acommunications interface, the anchor device comprising

a conductor receiving portion including a channel, the conductors beingpositionable through the channel; and

a fixation portion connected to the conductor receiving portion, thefixation portion adapted to be secured to the outer surface of the eye;

wherein the conductor receiving portion is configured to allow movementof the conductors relative to the fixation portion.

In the preceding aspects, by configuring the conductor receiving portionto allow movement of the channel and/or conductors positioned in thechannel, relative to the fixation portion, the fixation portion may besubstantially isolated from any movement of the channel and/or movementof the conductors positioned in the channel. The conductors may beconsidered to “float” to some extent within the anchor device. Theanchor device can stabilise the conductors as they extend out of theopening at the outer surface of the eye, while at the same time allowingfor a controlled degree of movement of the conductors at or adjacentthis location. The arrangement can reduce the possibility that movementof the conductors will unseat the anchor device or cause damage to theeye.

The conductors may be provided in a lead that extend from the deviceimplanted in the eye, through the anchor device, and to thecommunications interface. The lead may be positionable within thechannel of the conductor receiving portion. The lead may be moveablewithin the channel and/or the lead may be moveable relative to thefixation portion. The lead may be fixed within the channel at a portionof the channel only, e.g. fixed along a length of less than 50%, lessthan 40% or less than 30% of the channel. The channel may have first andsecond openings, such that lead can extend from the implanted devicethrough the first opening into the channel and extend through the secondopening out of the channel towards the communications interface, and thelead may be fixed at or adjacent one end of the channel only, e.g. thesecond opening only.

In one embodiment, the anchor device is adapted to locate over theopening in the outer surface of the eye. Therefore, the anchor devicemay provide support for the one or more conductors at the position thatthey extend out of the opening in the outer surface of the eye.Furthermore, the anchor device may shield the opening in the outersurface of the eye.

The anchor device may be employed in visual prosthesis apparatus inwhich the conductors travel from the device implanted in the eye of thepatient, out of the opening in outer the surface of the eye, to thecommunications interface remote from the eye. The device implanted inthe eye may include, for example, an array of electrodes configured toapply electrical current to retinal cells of an eye in order to providethe patient with a perception of vision. The array of electrodes may bepositioned in or on a substrate, e.g. a flexible substrate.

The communications interface may comprise a wirelesstransmitter/receiver or comprise an electrical connector (e.g. a plugsocket or “pedestal”), allowing for a wired or wireless connectionbetween the implanted device and an electrical component such as asignal generator or otherwise. The communications interface may bedirectly connected to, or form part of, the electrical component, or maybe separate from the electrical component. In one embodiment, thecommunications interface may comprise a connection point between theconductors and a signal generator such as an implantable signalgenerator. The communications interface may be attached to, or wholly orpartially implanted in, the side of the patient's head, or at anotherpart of the patient's anatomy.

The device implanted in the eye may be a device as described inApplicant's PCT Publication No. WO 2011/022773, for example, the contentof which is incorporated herein by reference, or it may be another typeof implantable device.

The conductors may extend in a helical and/or wavy configuration throughthe channel and/or other parts of the visual prosthesis apparatus, suchas the device implanted in the eye and/or the lead extending from theanchor device to the communications interface. By using helicallyconfigured conductors or conductors with a wavy shape, upon flexing ofthe apparatus, the conductors can effectively expand or contract inlength as necessary, avoiding damage to parts of the apparatus includingthe conductors themselves.

The fixation portion and the conductor receiving portion may each have abottom surface for locating on the outer surface of the eye. The bottomsurfaces may be substantially flush with each other. The bottom surfacesmay be curved to substantially follow the contours of the outer surfaceof the eye to ensure even contact with the eye when the anchor device issecured to the outer surface of the eye.

In addition to stabilising the conductors adjacent the outer surface ofthe eye, the anchor device may serve to route the conductors or leadincluding the conductors in an appropriate direction away from theanchor device and the eye, towards the communications interface, e.g.,past extraocular muscles of the eye and towards the lateral orbital rim.To achieve this, the channel within the anchor device may follow a bentpath. The channel path may bend by, for example, 45 to 135 degrees. Inone embodiment, the channel path may be a substantially right-angledpath, i.e. it may bend by about 90 degrees. In another embodiment, thechannel path may bend by about 50 to 70 degrees, e.g. about 55 or about60 degrees. The conductors or lead may be routed from the anchor devicealong a substantially horizontal path, or may be routed from the anchordevice along a path that is angled from horizontal. For example, thepath may be angled upwardly from horizontal, e.g. by about 20 to 30degrees or otherwise. It has been determined that such channel pathbends can provide improved routing of the conductors away from theopening in the outer surface of the eye, towards the communicationsinterface, in consideration of both positioning of the communicationsinterface and the locations of anatomical features at or adjacent theeye region, such as the extraocular muscles.

The channel in the conductor receiving portion may extend from a firstend of the anchor device adjacent the device implanted in the eye and asecond end of the anchor device adjacent the lead that extends to thecommunications interface. At or adjacent the first end, a first openingof the channel may be provided in the bottom surface of the conductorreceiving portion to directly receive the conductors as they extend outof the eye. At or adjacent the second end, a second opening of thechannel may be provided where the conductors exit the channel and travelthrough the lead to the communications interface. Accordingly, the firstopening may lie in a surface substantially parallel to the outer surfaceof the eye whereas the second opening may be lie in a surfacesubstantially normal to the outer surface of the eye.

In one embodiment, the fixation portion may be formed of the same orsimilar material as the conductor receiving portion. However, inalternative embodiments the conductor receiving portion may be formed ofmaterial that has greater flexibility and/or elasticity than thefixation portion, so that it is more adaptable to movement of theconductors and/or lead passing through the channel, while the fixationportion is more suitable for securing to the eye. The fixation portionand/or the conductor receiving portion may comprise a polymericmaterial, e.g. silicone. In the fixation portion, an additional elementmay be present which may provide for greater rigidity or inelasticity ofthe fixation portion, and which may not be present at all, or to thesame extent, in the conductor receiving portion. The additional elementmay form a core of the fixation portion or otherwise. The additionalelement may be a layer of relatively stiff or rigid material such as alayer of mesh, e.g., a mesh comprising polyethylene terephthalate. Inone embodiment, the conductor receiving portion comprises silicone only,and the fixation portion comprises silicone embedded with a polyethyleneterephthalate mesh (e.g. a Dacron™ mesh). The provision of thestiffening material in the fixation portion may prevent or limit thepossibility of sutures, which may be used to fix the anchor device tothe outer surface of the eye, from tearing the anchor device. However,the fixation portion may maintain some degree of flexibility/compliancy,ensuring that the fixation portion can conform more readily to the shapeof the outer surface of the eye. This stiffening material may bepositioned carefully to allow maximum strain relief (including in the zaxis) for the conductors and/or lead as they enter the anchor device.

The channel may be formed in the conductor receiving portion as a directresult of moulding material such as silicone over the conductors or leadcomprising the conductors to form the conductor receiving portion. As analternative approach, the channel may be preformed, with the conductorsbeing passed through the channel after forming.

The conductors may travel through a transition portion between thedevice implanted in the eye (the implantable device) and the anchordevice. For example, the conductors may extend out of a substrate of theimplantable device, through a transition lead section, before travellingthrough the anchor device. The transition portion may be flexible. Thelength of the transition portion may correspond to a thickness of tissueand/or the depth of the incision between the substrate of theimplantable device, at the conductor exit position, and the outersurface of the eye. To achieve flexibility, the transition portion, e.g.the transition lead section, may comprise a cladding material thatsurrounds the conductors and which is relatively flexible and/orrelatively narrow. For example, the transition portion may comprise aflexible polymeric material such as silicone that surrounds theconductors. Additionally or alternatively, the transition portion mayhave substantially no reinforcement where it is connected to theimplantable device, e.g. the substrate of the implantable device. Inthis regard, the transition portion may have no increase in diameter asit extends from the anchor device to the substrate or it may have adecrease in diameter as it extends from the anchor device to thesubstrate. By providing a flexible transition portion between theimplantable device and the anchor device, the anchor device can be lesslikely to impede or obstruct implantation of the implantable device. Theflexibility of the transition portion may allow for increased relativemovement between the anchor device and the implantable device during theimplantation process, minimising any potentially damaging forces beingtransferred from the anchor device to the implantable device via thetransition portion.

According to a third aspect, there is provided a lead configured toconnect a device implantable in an eye to a communications interfaceexternal to the eye, the lead comprising:

a reinforcement device, the reinforcement device having a first end anda second end and being elongated between the first end and the secondend, the reinforcement device being adapted to be positioned at oradjacent an orbital bone;

a first lead section connected to the first end of the reinforcementdevice;

a second lead section connected the second end of the reinforcementdevice; and

one or more conductors,

wherein the conductors are connectable to the implantable device and areconfigured to extend from the implantable device, through the first leadsection, the reinforcement device and the second lead section, to thecommunications interface,

wherein the reinforcement device has a greater outer diameter than thefirst and second lead sections.

The lead according to the third aspect may be employed in visualprosthesis apparatus that comprises the anchor device according to thefirst or second aspects.

The reinforcement device may have at least one bend region, a firstreinforcement section on the implantable device side of the bend region,and a second reinforcement section on the communications interface sideof the bend region. A channel may extend through each of these sectionsand the conductors may extend through the channel. The channel may beprovided within a third lead section positioned inside the reinforcementdevice. The first reinforcement section may have a length ofapproximately 0.5 to 3 cm, e.g. about 1.2 cm, and/or the secondreinforcement section may have a length of approximately 0.2 to 2 cm,e.g. about 0.5 cm. The bend region may maintain an angle between thefirst and second reinforcement sections of approximately 45° to 90°, orapproximately 55° to 70°, or about 63°, for example, or otherwise. Theouter diameter of the reinforcement device may be about 1 to 5 mm, e.g.about 2.5 mm, at the first reinforcement section, the secondreinforcement section and/or the bend region. The outer diameter of thelead may be about 0.5 to 3 mm, e.g. about 1 mm, at the first leadsection and/or the second lead section. Smooth or tapering transitionregions or ‘shoulders’ may be provided at one or both ends of thereinforcement device to reduce any trauma that may be caused at thetransition between the reinforcement device and the first and secondlead sections, when the reinforcement device is located in position.Similarly, a tapering transition region may be provided between theanchor device and adjacent portions of the lead. By providing a morestreamlined shape to the apparatus, greater strain relief may beprovided.

To secure the reinforcement device in position at the lateral orbitalrim, a notch may be formed in the orbital bone. The notch may have arecessed groove arranged to receive at least a portion of thereinforcement device, the groove being formed wider than an accessopening to the groove. This can allow the reinforcement device to bepress-fit through the opening into the groove, reducing the likelihoodthat the reinforcement device, when located in the groove, will bedisplaced from the groove. Nonetheless, adhesive material such as bonecement or a titanium bone plate may also be applied to the notch forextra security.

By employing the reinforcement device having a bend region, the leadcan, in effect, be pre-shaped to follow anatomy at the lateral orbitalmargin. This can make routing of the lead more straightforward andsecure. Pre-shaping may involve identification of appropriate3-dimensional geometry for the lead assembly dependent on the anatomy ofdifferent patients. Pre-shaping may include optimisation of the locationof the reinforcement device along the length of the lead, and may takeinto account differences between the left and right eyes to avoidtwisting of the lead either between the reinforcement device and theimplantable component or between the reinforcement device and thecommunications interface.

According to a fourth aspect, there is provided visual prosthesisapparatus including a device implantable in an eye, a communicationsinterface, and a lead extending between the implantable device and thecommunications interface, wherein the lead is pre-shaped tosubstantially follow the outer surface of the orbital bone at thelateral orbital rim adjacent the eye.

The lead may be pre-shaped by having a substantially fixed bend alongits length arranged to locate around the orbital bone at the lateralorbital rim. The fixed bend may be achieved, for example, by employing areinforcement device, e.g. as described with respect to the thirdaspect, or by configuring a bend in the cladding of the lead. In thelatter case, the bend region of the lead may have the same diameter asother sections of the lead.

According to a fifth aspect, there is provided a method for securing areinforcement device according to the third aspect to an orbital bone,comprising:

forming a notch in the orbital bone, wherein the notch comprises arecessed groove configured to receive the reinforcement device and anaccess opening through which the reinforcement device is locatable inthe recessed groove, wherein the access opening is narrower than therecessed groove.

In one embodiment, a dummy device may be used to assist with sizing ofthe notch including the recessed groove and the access, opening, whichdummy device may have substantially the same shape and dimensions as thereinforcement device, at least at regions of the reinforcement devicethat are to be located in the notch. The dummy device may be included ina surgical pack, along with one or more of the other items discussedherein, such as the anchor device, reinforcement device, and lead, etc.

According to a sixth aspect, there is provided apparatus for positioningcomponents of a visual prosthesis, the visual prosthesis including adevice implantable in an eye, a communications interface, and a leadextending between the implantable device and the communicationsinterface, the apparatus comprising:

an elongate element having a proximal end and a distal end, the distalend being insertable through a first incision in a skin surface of apatient, and movable under tissue towards a patient's eye, and

a handle portion releasably attachable to a proximal end region of theelongate element;

wherein the elongate element has a first recess at the distal endadapted to receive the implantable device and a channel extendingproximally from the first recess adapted to receive the lead, and

wherein the handle includes a second recess adapted to receive thecommunications interface.

According to a seventh aspect, there is provided a method of positioningcomponents of a visual prosthesis, the visual prosthesis including adevice implantable in a patient's eye, a communications interface, and alead extending between the implantable device and the communicationsinterface, the method comprising:

inserting a distal end of an elongate element through a first skinincision remote from the patient's eye, wherein the elongate elementhas:

-   -   a first recess at the distal end, the implantable device being        at least partially located in the first recess, and    -   a lead channel extending proximally from the first recess, the        lead being at least partially located in the lead channel, and        wherein    -   a handle is releasably attached to a proximal end of the        elongate element, the handle including a second recess, the        communications interface being at least partially located in the        second recess;

moving the distal end of the elongate device under tissue towards thepatient's eye;

pushing the distal end of the elongate device out of a second skinincision adjacent the patient's eye;

removing the implantable device from the first recess;

releasing the handle portion from attachment with the elongate element;

removing the communications interface from the second recess; and

pulling the elongate element out of the second skin incision.

The apparatus and method of the sixth and seventh aspects may be used inconjunction with visual prosthesis apparatus as described above withrespect to preceding aspects. In line with this, the implantable devicerecess may be configured such that the anchor device described withrespect to the preceding aspects is also locatable in the first recess(or located elsewhere in the elongate device) and/or the reinforcementdevice is located in the lead channel (or located elsewhere in theelongated device). The apparatus and method may be used to locate theimplantable device beyond the second skin incision at a positionadjacent the patient's eye, e.g. at the lateral orbital margin, so thata surgeon may take hold of the implantable device immediately prior tosurgical implantation in the eye. At the same time, the lead may beconnected to the implantable device and remain routed under thepatient's skin or tissue, along the side of the patient skull, to thefirst incision, adjacent to which the communications interface may besecured to the skull.

The apparatus and method may employ a dummy element to create a pocketunder tissue between the first and second skin incisions prior to movingthe elongate element between the first and second skin incisions. Thedummy element may have a similar or identical profile (external size andshape) to the elongate element. The dummy element may therefore be usedto ensure that the elongate element will be moveable more easily betweenthe incisions.

The elongate element, which may also be referred to as a “trocar” or“trochar” or otherwise, may include a head at its distal end thatincludes the first recess for the implantable device and an armextending proximally therefrom that includes the lead channel, whereinthe lead channel has an opening at its distal end that opens into thefirst recess. The head may be substantially wider than the arm. Thehead, which will provide a leading end of the elongate device when it isinserted under the skin, may have a smooth, streamlined shape tominimise surgical trauma. The streamlined shape may be achieved throughthe provision of a curved distal edge or tip to the head, throughforming the head in a relatively flat configuration and/or by providingsmooth shoulder portions that join the head to the arm. The flatconfiguration of the head may allow the head to maintain a relativelylow profile against the skull while under the skin.

To encase the implantable device within the first recess duringinsertion, a lid may be provided. The lid may attach the head in apress-fit manner. The apparatus may include a key operable to releasethe lid.

The positioning apparatus may be formed of strong and rigid material,e.g. surgical steel, such as to prevent compressive forces damaging thevisual prosthesis apparatus located therein. However, in someembodiments, parts of the positioning apparatus may have flexibility tomake navigation of portions of the apparatus under tissue, for example,more straightforward.

The handle may include first and second portions that clamp together onopposite sides of the arm, fixing the position of the handle relative tothe arm. The clamping may also be used to retain the communicationsinterface in the second recess. The first and second handle portions maybe clamped together using a bolt, clasp or otherwise. A releasemechanism may be provided to release the clamping, which release may beperformed by hand, e.g. using one hand. The release mechanism may be anut at the end of a bolt, although alternative approaches are possible.

While the apparatus and method of the sixth and seventh aspects isdescribed in conjunction with a visual prosthesis, the apparatus andmethod can also be used, mutatis mutandis, with other prosthetic devicesemploying electrical and implantable components.

Thus, according to an eighth aspect, there is provided positioningapparatus for positioning components of electrical apparatus, theelectrical apparatus including a device implantable at a target portionof a patient's body, a communications interface, and a lead extendingbetween the implantable device and the communications interface, thepositioning apparatus comprising:

an elongate element having a proximal end and a distal end, the distalend being insertable through a first incision in a surface of a patient,and movable under tissue towards the target position, and

a handle portion releasably attachable to a proximal end region of theelongate element;

wherein the elongate element has a first recess at the distal endadapted to receive the implantable device and a channel extendingproximally from the first recess adapted to receive the lead, and

wherein the handle includes a second recess adapted to receive thecommunications interface.

Further, according to a ninth aspect, there is provided a method ofpositioning components of electrical apparatus, the electrical apparatusincluding a device implantable at a target position in a patient's body,a communications interface, and a lead extending between the implantabledevice and the communications interface, the method comprising:

inserting a distal end of an elongate element through a first incisionremote from the target position, wherein the elongate element has:

-   -   a first recess at the distal end, the implantable device being        at least partially located in the first recess, and    -   a lead channel extending proximally from the first recess, the        lead being at least partially located in the lead channel, and        wherein    -   a handle is releasably attached to a proximal end of the        elongate element, the handle including a second recess, the        communications interface being at least partially located in the        second recess;

moving the distal end of the elongate device under tissue towards thetarget position;

pushing the distal end of the elongate device out of a second incisionadjacent the target position;

removing the implantable device from the first recess;

releasing the handle portion from attachment with the elongate element;

removing the communications interface from the second recess; and

pulling the elongate element out of the second incision.

The apparatus and method of the eighth and ninth aspects may be used,for example, in conjunction with any apparatus that employs animplantable electrical component such as an electrode array, theimplantable component having a lead extending therefrom that is adaptedto connect the implantable component to a communications interface byextending under body tissue. The electrical component may be providedfor the purposes of electrostimulation and/or electrical monitoring. Thetarget position for the implantable component may be in or on apatient's eye or head, or may be elsewhere in the body.

In one embodiment, the electrical apparatus may be adapted to diagnose,limit or prevent onset of epileptic seizures, and/or to monitor bodyparameters associated with epileptic seizures. The implantable devicemay include an electrode array that is adapted to be placed within ornear the source or sources of seizures in the brain. The electricalstimulus may be applied by the electrodes to terminate or at leastcounteract epileptic seizure events arising from those sources and/orthe electrodes may be used to monitor electrical activity within or nearthe source or sources of seizures in the brain.

The elongate element can be bent or shaped to a curvature as appropriatefor a particular application (e.g. as appropriate for the geometry ofthe body where components of the electrical apparatus are to bepositioned). In the case of the epilepsy procedure, the elongate elementcan have a curvature matched to the patient's skull in order to minimisesurgical trauma to the patient. Whole or parts of the elongate elementcan be bent, shaped or curved.

The elongate element can be fabricated from a variety of differentmaterials included metal (e.g. stainless steel, titanium, Nitinol™),and/or medical grade plastic (Teflon™, PEEK etc), in order to achieve anappropriate flexibility of the elongate element to allow bending. Theelongate element may have different degrees of flexibility in differentplanes or directions, depending on the desired application of theapparatus. For example, the elongate element may be configured toexhibit relative rigidity when pushed from one end, but exhibit relativeflexibility when pushed from a top or bottom face. This may ensure thatthe elongate element can perform a reliable tunnelling function undertissue, while enabling it to be bent around curved anatomicalstructures.

The apparatus and method of the sixth to ninth aspects may be used inconjunction with a once-piece implantable device and stimulator system.The communications interface may form part of a signal generator, whichis connected to the implantable device during the positioning procedure,rather than being positioned independently and only connected togetherafter implantation, for example. The signal generator may be implantableand the signal generator may be at least partially located, in thesecond recess

BRIEF DESCRIPTION OF THE DRAWINGS

By way of example only, embodiments are now described with reference tothe accompanying drawings, in which:

FIG. 1 a shows a top view of visual prosthesis apparatus, including animplantable device, an anchor device, and a lead, according to anembodiment of the present disclosure; and FIG. 1 b shows a variation ofthe visual prosthesis apparatus of FIG. 1 a;

FIGS. 2 a and 2 b show photographic top and bottom views, respectively,of visual prosthesis apparatus configured generally in accordance withthe apparatus of FIG. 1 a;

FIGS. 3 a to 3 c represent example steps for surgically implanting theimplantable device of the visual prosthesis apparatus of FIG. 1 a in aneye;

FIGS. 4 a and 4 b show example positioning of the implantable device ofthe visual prosthesis apparatus of FIG. 1 a relative to the corneallimbus and the optic disk, respectively;

FIGS. 5 a and 5 b show front and side views of an eye socket with theanchor device and lead of the visual prosthesis of FIG. 1 a positionedfor use;

FIGS. 6 a and 6 b show top and oblique views, respectively, of an anchordevice according to an alternative embodiment of the present disclosure;

FIGS. 7 a to 7 c each show a top view of the anchor device of FIG. 6 ain which the positioning, with respect to the device, of sutures, glue,and mesh, respectively, is indicated;

FIG. 8 shows a top view of an anchor device according to an alternativeembodiment of the present disclosure;

FIGS. 9 a and 9 b show routing of the lead at the surface of the eyeusing an anchor device in accordance with FIG. 1 a and FIG. 6 a,respectively.

FIG. 10 shows a notch in an orbital bone of the eye socket of FIGS. 5 aand 5 b configured to receive a reinforcement device of the visualprosthesis apparatus of FIG. 1 a;

FIG. 11 shows routing of the lead of the visual prosthesis apparatus ofFIG. 1 a relative to a skull;

FIG. 12 shows an exploded oblique view of positioning apparatusaccording to an embodiment of the present disclosure;

FIG. 13 shows an oblique view of the positioning apparatus of FIG. 12 ina complete state;

FIG. 14 shows an oblique view of a communications interface locatable inthe positioning apparatus of FIG. 12;

FIG. 15 shows an oblique view of a dummy trocar;

FIG. 16 shows a side view of a trocar according to an alternativeembodiment of the present disclosure; and

FIG. 17 shows positioning of apparatus components following use of thetrocar of FIG. 16.

DETAILED DESCRIPTION OF EMBODIMENTS

Various embodiments of the present disclosure relate to visualprosthesis apparatus that employs conductors configured to extend from adevice implanted in an eye to a communications interface remote from theeye. The interface may be a plug pedestal or other type of connector,and may comprise a wireless transmitter/receiver or comprise electricalconnections for wired communication. The interface may therefore providefor wired or wireless connection between the implanted device andadditional electrical components of the visual prosthesis apparatus,which additional components may be implantable or otherwise. Theinterface may be attached to, or wholly or partially implanted in, theside of the patient's head (or other part of the patient's anatomy).

Throughout this specification the term “visual prosthesis apparatus” isused to denote apparatus for improving a patient's vision (or at leastgiving improved “perception” of vision), and will be understood toinclude devices otherwise known as bionic eyes, artificial eyes, retinalprostheses and retinal stimulators or similar. However, features of thepresent disclosure may be useable with any type of device implanted inthe eye, whether for sight restoration or otherwise, or with entirelydifferent types of implantable devices, including devices adapted tostimulate or monitor brain activity.

FIG. 1 a shows a top view of visual prosthesis apparatus according to anembodiment of the present disclosure, the apparatus including animplantable device 1, an anchor device 2 and a lead 3. To further aidunderstanding, photographic depictions of visual prosthesis apparatusconfigured generally in accordance with the apparatus of FIG. 1 a areprovided in FIGS. 2 a and 2 b, and corresponding reference numerals areused to identify corresponding components for simplicity.

The implantable component 1 has a flexible substrate 10 with a distalend 11 and a proximal end 12. The substrate 10, when viewed from above,is substantially rectangular, with curved corners to minimise surgicaltrauma, its longitudinal direction extending between the distal andproximal ends 11, 12. Adjacent the distal end 11 of the substrate 10, anarray of electrodes 13 is provided for applying electrical current toretinal cells of an eye. Each electrode 13 is connected to a separateelectrical conductor, e.g., a biocompatible metal wire 14 such as aplatinum wire. As the conductors 14 extend from the electrodes 13through the substrate 10 towards the proximal end 12 they are bunchedtogether in helical or wavy configurations, along two spaced paths 141,142. By using helically configured conductors or wave shaped conductors,both in the substrate 10 and elsewhere in the apparatus, upon flexing ofthe apparatus, the conductors can effectively expand or contract inlength as necessary, avoiding damage to components of the apparatusincluding the conductors themselves.

The two conductor paths 141, 142 joint together at the proximal end 12of the substrate 10, adjacent an exit point of the conductors from thesubstrate 10. At the exit point, the conductors 14 continue along asingle helical path, passing through the anchor device 2 and thenextending further on through the lead 3.

An example method of implanting the substrate 10 in an eye is nowdiscussed with respect to FIGS. 3 a to 4 b. An incision 40 is made inthe sclera 41 of the eye with a scalpel 42, the incision 40 beingslightly wider than the width of the substrate 10 (FIG. 3 a). The distalend 11 of the substrate 10 is then pushed into the incision, usingsoft-tipped forceps 43, through the scleral layer and into a pocketbetween the sclera and the choroid (FIG. 3 b). Once fully inserted, theopening of the incision is closed using sutures 44 (FIG. 3 c). In thisexample, as represented in FIGS. 4 a and 4 b, the incision 40 is about 5mm from the corneal limbus 45 and the substrate 10, when fullyimplanted, locates entirely between the sclera and choroid layers of theeye. The electrodes 13 locate adjacent the active cells of the eye'sretina, about 2 mm to 4 mm, e.g. 3 mm to one side of the optic disc 46(in FIGS. 4 a and 4 b, the location of the substrate 10 under the sclerais indicated by dotted lines 10′ and, for simplicity, neither the anchordevice 2 nor the lead 3 is represented in FIGS. 3 a to 4 b).

The anchor device 2 is used to stabilise the conductors 14 at the exitpoint of the eye, prior to routing of the lead 3 towards acommunications interface. The anchor device 2 also serves to channel theconductors 14 in an appropriate direction away from the eye, towards thecommunications interface. FIGS. 5 a and 5 b show front and top views,respectively, of an eye socket region showing possible locationpositions for the anchor device 2 in relation to the eye, and routing ofthe lead 3 from the eye, past the extraocular muscles 49 and around theorbital bone 47 at the lateral orbital margin. The anchor device 2, andindeed the incision 40 where it is located, are strategically positionedon the sclera 41 to avoid interfering with the extraocular muscles 49.Particularly, the incision 40 in this embodiment is positioned behindthe connection between the eye and the lateral rectus muscle, and theanchor device 2 is configured to direct the lead 3 rearward, over thetop of the lateral rectus muscle and between the lateral rectus muscleand the superior rectus muscle.

Referring again to FIG. 1 a, the anchor device 2 includes a fixationportion 21 that is configured to be secured to the sclera of the eye,and a conductor receiving portion 22 having a channel 23 through whichthe lead 3, which encloses the conductors 14, extends. In thisembodiment, the fixation portion 21 and receiving portion 22 are bothformed at least in part of silicone, although other flexible polymers orindeed other types of materials may be used.

In one embodiment, the channel 23 can be formed as a direct result ofmoulding silicone over the lead 3 and/or conductors 14. Alternatively, achannel may be preformed in the receiving portion 22 with the conductorsbeing passed through the channel after forming of the channel. The shapeof at least the fixation portion 21 may be varied. For example, it maybe extended or widened to provide a larger fixation area.

In this embodiment, the lead 3, while extending through the entirelength of the channel 23 of the receiving portion 22, is fixed to thereceiving portion 22 adjacent one end of the channel 23 only; inparticular, adjacent the end of the channel 202 opposite to theimplantable device 1. By fixing the lead 3 adjacent one end only,greater movement of the non-fixed portions of the lead 3 within theconfines of the channel 23 is possible. The channel 23 can be sized sothat it has a diameter larger than the diameter of the lead 3, allowinggreater movement. To this end, gaps can exist between the lead 3 and thechannel walls. The gaps may be filled with body fluid during use.

The fixation portion 21 includes a relatively flat piece of silicone inwhich a layer of polyethylene terephthalate (PET) mesh 24 is embedded,increasing the rigidity and strength of the fixation portion 21.Accordingly, while silicone covering the mesh 24 provides the fixationportion 21 with a relatively conformable surface suitable for engagementwith the eye, the size and shape of the fixation portion 21 remainssubstantially fixed by the mesh 24. Thus, the fixation portion 21provides a firm, relatively flat, platform for engaging and securing theanchor device 2 to the outer surface of the eye.

The conductor receiving portion 22 includes no reinforcing mesh layer inthis embodiment and is therefore relatively flexible in comparison tothe fixation portion 21. The receiving portion 22 maintains a gapbetween the channel 23 and the fixation portion 21, and thus provides arelatively flexible transition region between the channel 23, includingthe lead and conductors 14, and the fixation portion 21, allowing acontrolled degree of movement therebetween. The movement can ensurethat, while the anchor device 2 provides a secure path for theconductors 14 to exit the incision 40 in the eye, the conductors 14 maystill flex, e.g. during rotation of the eye, reducing the likelihood ofdamage to the eye at the exit point, or possible breakage occurring tothe conductors 14.

Referring to FIG. 2 b, the bottom surface 221 of the receiving portion22 is substantially flush with the bottom surface 211 of the fixationportion 21 to ensure that a reliable contact between the anchor device 2and the eye can be achieved with relatively even force distributionacross the anchor device 2. The bottom surfaces 211, 221 are curved tofollow substantially the curvature of the outer surface of the sclera ofthe eye. Referring to FIG. 2 a, the top surface 222 of the receivingportion 22 protrudes further than the top surface 212 of the fixationportion 21 to accommodate the channel 23 and the lead 3/conductors 14.

In this embodiment, the conductor receiving portion 22 and the channel23 follow a bent, substantially right-angled, path between a first end201 of the anchor device 2 adjacent the substrate 10 and a second end202 of the anchor device 2 where the lead extends from the anchor device2 towards the communications interface. The conductor receiving portion22 and channel 23 extend right up to the second end 202 of the anchordevice 2, where the channel 23 has a second opening 204 through whichthe lead 3/conductors 14 exit the channel. However, the conductorreceiving portion 22 has an opposite first opening 203 (see FIG. 2 b),through which the lead 3/conductors 14 enter the anchor device 2, from aposition adjacent the substrate 10, that is set back from the first end201 of the anchor device 2 and that is provided in the bottom surface221 of the conductor receiving portion 22. This allows the fixationportion 21 to provide for increased support adjacent the incision 40 inthe eye by extending around the conductor receiving portion 22 on threeof its sides. It also allows the first opening 203 to lie against thesclera of the eye so that the conductors 14 can enter the anchor device2 directly from the incision in the eye, permitting sealing or shieldingto be achieved at this position.

The apparatus comprises a transition portion between the anchor device 2and the implantable component 1. In particular, the lead 3 has asection, described herein as a transition lead section 31 and which iscircled in FIG. 2 b, that extends between a position of the substrate 10at which the conductors 14 exit the substrate 10 and the first opening203 of the anchor device 2. The length of the transition lead section 31corresponds substantially to a thickness of tissue/the length of theincision through which the lead 3 extends from the substrate and exitsthe eye.

The transition lead section 31 tapers towards the substrate 10 and thusprovides a relatively flexible section of the lead adjacent thesubstrate 10. The transition lead section 31 therefore provides aflexible transition portion between the implantable component 1 and theanchor device 2, and the anchor device 2 can therefore be less likely toimpede or obstruct implantation of the implantable component. Theflexibility of the transition portion may allow for increased relativemovement between the anchor device 2 and the implantable component 1during the implantation process, minimising any potentially obstructiveforces being transferred from the anchor device 2 to the implantablecomponent 1 via the transition portion.

In the embodiments described above with reference to FIGS. 1 a to 2 b,the conductor receiving portion 22 and the channel 23 of the anchordevice 2 follow a bent, substantially right-angled path between a firstend 201 of the anchor device 2 adjacent the substrate 10 and a secondend 202 of the anchor device 2 where the lead extends from the anchordevice 2 towards the communications interface. However, with referenceto FIGS. 6 a and 6 b, in an alternative embodiment, an anchor device 2′can be provided in which the conductor receiving portion 22′ and thechannel can follow a bent path than is not right angled. For example apath may bend by only about 50° to 60°. It has been determined that thiscan allow the lead 3 to be optimally routed away from the opening in theouter surface of the eye, towards the communications interface, inconsideration of the location of the communications interface and theposition of anatomical features such as the extraocular muscles. FIGS. 9a and 9 b depict the different routes that can be taken by the lead 3from the incision in the eye 40, towards the communications interface,when channel bends of about 90° and about 50° to 60° are employed in theanchor device 2, 2′, respectively. By providing these channel bends, thelead can be routed substantially horizontally across the eye from theanchor device or angled upwardly from horizontal at an angle of about20° to 30°.

FIGS. 7 a to 7 c each show a top view of the device of FIG. 6 a in whichthe positioning, with respect to the device, of sutures, glue, and meshis indicated. In more detail, FIG. 7 a shows possible connectionpositions 25 for sutures, which sutures may be used to fix the fixationportion 21′ of the device 2′ to the outer surface of the eye. The sutureconnection positions 25 on the fixation portion 21′ may be reinforced.FIG. 7 b shows positions at which glue 26 (or other fixation means) maybe used to connect the lead within the channel of the conductorreceiving portion 22′. The lead is fixed adjacent the end 202′ of thechannel that is opposite to the implantable device, and is fixed along arelatively small percentage of the length of the channel, e.g. less than50%, less than 40% or less than 30% of the length of the channel. Asdiscussed above, by fixing the lead adjacent one end only, greatermovement of the non-fixed portions of the lead within the confines ofthe channel is possible. FIG. 7 c shows location positions for the mesh24′ used to stiffen/reinforce the fixation portion 21′. The positioningand shape of the mesh 24′ may allow improved progressive 3-dimensionalstrain relief on the entry point for the lead into the anchor device 2′.The mesh 24′ is tapered to minimise stress at this point.

FIG. 8 shows a top view of an anchor device 2″ according to analternative embodiment of the present disclosure. The anchor device 2″is similar to the anchor device 2′ described with reference to FIGS. 6 ato 7 c. However, the fixation portion 21″ of the device has beenextended to support increased torsional forces that may result from useof a stiffer lead, for example.

The lead 3 includes silicone cladding that surrounds the helicallyarranged conductors 14. Referring to FIG. 1 a, at approximately 3 to 4cm along the lead from the substrate, the lead 3 is provided with areinforcement device, referred to hereinafter as a “grommet” 4, thatboth directs the conductors 14 around the orbital bone 47 of the eyesocket, as shown in FIGS. 5 a and 5 b, and provides protection for theconductors 14 against high stresses at this region. After extendingaround the orbital bone 47, the lead 3 extends along the side of thepatients skull 43 to a communications interface (plug pedestal 5 in thisembodiment), as shown in FIG. 11. A return electrode 53 is connected tothe pedestal 5.

The grommet 4 has a bend region 402, a first section 401 on theimplantable device side of the bend region 401, and a second section 403on the communications interface side of the bend region 402. A channelextends through the first and second sections 401, 403 and the bendregion 402 in which the lead 3/conductors 14 are located. The firstsection 401 has a length of approximately 0.5 cm and the second section403 has a length of approximately 1.2 cm. The bend region 402 maintainsan angle between the first and second sections 401, 403 of e.g. 63 °.

With reference again to FIGS. 5 a and 5 b, and to FIG. 10, the grommet 4is configured for location in a notch 48 that is formed in the orbitalbone 47 by the surgeon. The notch 48 has a recessed groove 481, arrangedto receive the grommet 4, that is formed wider than an access opening482 to the groove 481. This allows the grommet 4 to be press-fit throughthe opening 482 into the groove 481, reducing the likelihood that thegrommet 4, when located in the groove 481, will be displaced from thegroove 481. A dummy device may be used to assist a surgeon with sizingof the notch 48 including the recessed groove 481 and the access opening482, which dummy device may have substantially the same shape anddimensions as the grommet 4, at least at regions of the grommet 4 thatare to be located in the notch 48. The dummy device may be included in asurgical pack, along with one or more of the other items discussedherein, such as the anchor device, grommet, and lead, etc.

In an alternative embodiment as shown in FIG. 1 b, a grommet 4′ may beprovided having more than one bend. For example, it may have a firstbend region 402 a and a second bend region 402 b. The bends at regions402 a and 402 b are in different directions and are appropriate fornavigating the orbital bone and enabling the lead to project off thebone surface. The second bend 402 b may direct the lead upwards by about20°, for improved intraorbital lead fit in patients. In otherembodiments, the grommet may have 3 or more bend regions. Additionally,the grommet 4′ can have one or more lugs 404 to help achieve pressurefitting in the groove 481. The lugs 404 can project from opposite sidesof the grommet 4′.

Apparatus for positioning components of the visual prosthesis apparatus,e.g. as shown in FIGS. 1 a to 9 b and 11, is now discussed with respectto FIGS. 12 to 15.

The apparatus comprises an elongate element 61, referred to hereinafteras a “trocar”, which is configured to hold, during positioning, animplantable device and a lead connected to the implantable device, andoptionally an anchor device and reinforcement device. The implantabledevice, anchor device, lead and reinforcement device may be configuredin accordance with the implantable device 1, anchor device 2, 2′, 2″,lead 3, and reinforcement device 4, described above with respect toFIGS. 1 a to 9 b and 11 or otherwise.

In this embodiment, positioning involves passing the trocar through afirst skin incision remote from the patient's eye, tunnelling the trocarunder tissue along the patient's skull, and passing the trocar out of asecond skin incision adjacent the patient's eye. By performing thesesteps, it is possible to locate the implantable device at a positionadjacent the patient's eye where the surgeon may take hold of theimplantable device for the purposes of surgical implantation. At thesame time, the lead that is connected to the implantable device canremain routed under the patient's tissue, along the side of the patientskull, to the first incision, where a communications interface (plugpedestal 5 in this embodiment) is positioned.

The first incision may be made in the posterior temporalis muscle suchas to expose a flat section of squamous temporal zone, where the plugpedestal may be secured after the periosteum is dissected, for example.The second incision may be made at the lateral orbital margin, forexample.

Referring to FIG. 12, the trocar 61 includes a head 62 and an arm 63.The head 62 is located at a distal end 611 of the trocar 61, and the arm63 extends from the head 62 to a proximal end 612 of the trocar 61. Thehead 62 is substantially wider than the arm 63 and includes a shallowcavity 621 dimensioned to receive the implantable device, and optionallyalso an anchor device, in a securely packed manner. The arm 63 includesa channel 631 that is open to the cavity 621 and extends proximallyalong the direction of elongation of the arm 63 to a position abouthalfway along the length of the arm 63. The channel 631 is configured toreceive the lead, and optionally also the reinforcement device, when theimplantable device is located in the cavity 621. The length of thechannel is such that it can receive a lead having a length that, whenlocated under the skin, provides sufficient slack to allow surgicalimplantation of the implantable device.

The head 62 provides a leading end to the trocar 61 when it is insertedand tunnelled under the skin. External surfaces of the head 62 aretherefore configured in a smooth, streamlined shape to minimise surgicaltrauma. The streamlined shape is achieved at least through the provisionof a curved distal tip 622 to the head 62, through forming the head 62in a relatively flat configuration, and by providing gently shelvingshoulder portions 623 that join the head 62 to the arm 63 without anysharp corners. The flat configuration of the head 62 in particularprevents significant damage occurring to tissue during transfer beneaththe skin, since it allows the head 62 to maintain a relatively lowprofile against the skull while under the skin, prior to it beingextended out of the second incision. Nonetheless, prior to insertion ofthe trocar 61 through the first skin incision, a tunnel may be createdfrom the first incision towards the lateral orbital rim to make transferof the trocar 61 towards the second skin incision more straightforward.The tunnel may be made beneath the temporalis fascia. The tunnel may bemade using a dummy trocar 8 with outer dimensions identical to theimplantable device and lead routing trocar 61, as shown in FIG. 15.

To encapsulate the implantable device within the cavity during transferunder the skin, a lid 65 is provided. The lid 65 fits over the cavity621 and connects to the head 62 around a rim of the cavity 621 in apress-fit manner, generally as shown in FIG. 13. The cavity 621, lid 65and channel 631 are also configured in a smooth and streamline shape toremove any internal catch points in the trocar 61 that could causedamage to the visual prosthesis components located therein. The cavity621 is configured such that, when closed by the lid 65, it has idealpacking dimensions for the implantable device located therein.

One or more notches 623, 651 are provided in the head 62 that allow forinsertion of a key 66. The key 66 can be turned in the notches 623, 651to prise open the lid 65, allowing access to the cavity 621 once thehead 62 has been extended though the second incision adjacent the eye.Once access is achieved, the surgeon can remove the implantablecomponent from the cavity 621, e.g. using forceps, and manipulate theimplantable component for implantation in the patient's eye. Whiletunnelling under the patient's skin, compressive forces of the skintissue assist in maintaining the lid 65 in a closed position. Thepositioning apparatus is formed generally of sufficiently strong andrigid material, e.g. surgical steel, such as to prevent compressiveforces damaging the visual prosthesis apparatus.

A handle 7 is positioned at a proximal end region of the arm 63,providing both a grip region for the surgeon to hold when guiding thetrocar 61 and a means for retaining the plug pedestal 5. In thisembodiment, with reference to FIG. 14, the plug pedestal 5 comprises abase 51 and a boss 52 extending therefrom, and includes electricalcontacts for connecting with external electrical components. The plugpedestal 5 is a percutaneous plug pedestal, configured to be locatedpartially under the patient's skin where it is fixed to the patient'sskull, e.g. using bone screws such as self tapping screws. Prior tosecuring, the periosteum may be dissected.

The handle 7 has an ergonomic shape for ease of handling and use andincludes first and second handle halves 71, 72 that clamp together onopposite sides of the arm 63 to form the handle, fixing the position ofthe handle 7 relative to the arm 63 while retaining the plug pedestal 5at the distal end of the handle 7. When the handle halves 71, 72 areclamped to the arm 63, the arm locates in a retention groove 711 locatedon an inside surface of the first handle half 71. Furthermore, the base51 of the plug pedestal locates in a recess 712 at the distal end of thefirst handle half 71 and abuts against a step 632 in the arm 63 at theproximal end of the channel 631. Meanwhile the boss 52 extends through arelief 721 at the distal end of the second handle half 72. A groove 715is also provided in the first handle half 71 that receives a returnelectrode 53 (see also FIG. 11). The clamping arrangement maintains thepedestal 5 and the return electrode 53 in a secure position at anopposite end of the lead 3 to the implantable device, during positioningof the apparatus.

The handle halves 71, 72 are secured together using a bolt 73. The bolt73 extends through holes 713, 722 provided in each of the handle halves71, 72. The bolt 73 has a head end 731 that locates in a recess 714 onthe outer side of the first handle half 71, and has a threaded body 732that passes through the holes 713, 722 and engages with a nut 74 locatedto the outer side of the second handle half 72. The nut 74 is knurledand can be turned relatively easily using the thumb and finger to enablethe handle halves 71, 72 to be separated and the handle 7 to be releasedfrom the trocar 63. The groove 715 is configured such that, duringseparation of the handle halves 71, 72, the return electrode 53 is drawnout of the groove, e.g. ready for implantation under skin behind theear. By allowing for relatively easy release of the handle 7, after theapparatus has been used to transfer the implantable device and lead intoposition, the trocar 61 can be removed through the second incision atthe orbital margin in the same direction as it was moved under thepatient's skin from the first incision, without obstruction by thehandle (the handle need never be extended under the skin). By pullingthe trocar through the second incision at the lateral orbital rim,rather than retracting it back through the first incision adjacent theear, surgical trauma can be minimised.

While the positioning apparatus and methods described above withreference to FIGS. 12 to 15 are used in conjunction with visualprosthesis apparatus, similar positioning apparatus and methods can beused to position other apparatus that employs electrical and implantablecomponents. For example, similar positioning apparatus and methods canbe used in conjunction with apparatus including a component that isimplantable in or on the brain. One example of this is apparatus adaptedto limit or prevent onset of epileptic seizures, and/or to monitor bodyparameters associated with epileptic seizures, and which employs anelectrode array that is adapted to be placed within or near the sourceor sources of seizures in the brain. Electrical stimulus can be appliedby the electrodes to terminate or at least counteract epileptic seizureevents arising from those sources and/or the electrodes can be used tomonitor electrical activity within or near the source or sources ofseizures in the brain.

Referring to FIGS. 16 and 17, such apparatus can employ a trocar 9 (andoptionally a corresponding dummy trocar) that is configured insubstantially the same manner as described with reference to FIGS. 12,13 and 15, but which has a head at the distal end 901 with a firstrecess dimensioned instead to receive an implantable device 91,including a plurality of electrodes, for use with epilepsy treatment,and which trocar is curved to follow the curvature of the skull betweenan appropriate implantation position towards the top of the skull and alocation position for a communications interface 92 (e.g. pedestal).

As before, a handle (not shown) is releasably attached to a proximal end902 of the trocar 9 and the communications interface 92 is at leastpartially located in the handle. The implantable device 93 is at leastpartially located in the first recess adjacent the distal end 901 of thetrocar. The trocar has a lead channel extending proximally from thefirst recess with a lead, that connects between the implantable deviceand the communications interface, at least partially located in the leadchannel. The distal end 901 of the trocar 9 is inserted through a firstincision 94 adjacent the ear and tunnelled under tissue towards thetarget position. The distal end of the trocar 9 is then pushed out of asecond incision 95 adjacent the target position and the implantabledevice is removed from the first recess. The handle is then releasedfrom attachment with the trocar 9 and the communications interface isreleased from the handle. The trocar 9 is pulled out of the second skinincision 95. The implantable device is manually inserted into a tissuepocket under the patient's scalp, sutured in place and the incisions(wounds) are closed.

It will be appreciated by persons skilled in the art that numerousvariations and/or modifications may be made to the above-describedembodiments, without departing from the broad general scope of thepresent disclosure. The present embodiments are, therefore, to beconsidered in all respects as illustrative and not restrictive.

1. An anchor device adapted to support one or more conductors extendingout of an opening in an outer surface of an eye, from a device implantedin the eye to a communications interface, the anchor device comprising:a conductor receiving portion including a channel, the conductors beingpositionable through the channel; and a fixation portion connected tothe conductor receiving portion, the fixation portion being adapted tobe secured to the outer surface of the eye; wherein the conductorreceiving portion is configured to allow movement of the channel and/orconductors relative to the fixation portion.
 2. The device of claim 1,wherein the anchor device is adapted to locate over the opening in theouter surface of the eye.
 3. The device of claim 1 or 2, wherein theconductors extend through a lead connected to the implanted device, theconductor receiving portion being configured to allow movement of thelead relative to the fixation portion.
 4. The device of claim 3, whereina portion of the lead is fixed in the channel.
 5. The device of claim 4,wherein a portion of the lead is fixed adjacent one end of the channelonly.
 6. The device of claim 3, 4 or 5, wherein the channel has adiameter greater than the diameter of the lead such that at least aportion of the lead within the channel can move relative to the channel.7. The device of any one of the preceding claims, wherein the conductorsextend in a helical configuration through the channel.
 8. The device ofany one of the preceding claims, wherein the fixation portion and theconductor receiving portion each have a bottom surface for locating onthe outer surface of the eye.
 9. The device of claim 8, wherein thebottom surfaces are curved to substantially follow the contours of theouter surface of the eye.
 10. The device of any one of the precedingclaims, wherein the channel follows a bent path.
 11. The device of claim10, wherein the channel has a bend of approximately 90 degrees.
 12. Thedevice of claim 10, wherein the channel has a bend of approximately 50to 60 degrees.
 13. The device of any one of the preceding claims,wherein the channel extends from a first end of the anchor deviceconfigured to locate adjacent the implantable device and a second end ofthe anchor device configured to locate adjacent a lead section extendingto the communications interface.
 14. The device of claim 13, wherein, ator adjacent the first end, a first opening of the channel is provided ina bottom surface of the conductor receiving portion, the bottom surfacebeing configured to locate substantially parallel to the outer surfaceof the eye.
 15. The device of claim 13 or 14, wherein, at or adjacentthe second end, a second opening of the channel is provided in a sidesurface of the conductor receiving portion, the side surface beingconfigured to locate substantially normal to the outer surface of theeye.
 16. The device of any one of the preceding claims wherein theconductor receiving portion has greater flexibility and/or elasticitythan the fixation portion.
 17. The device of any one of the precedingclaims, wherein the fixation portion and/or the conductor receivingportion comprises silicone.
 18. The device of any one of the precedingclaims, wherein the fixation portion comprises a stiffening core. 19.The device of any one of the preceding claims, wherein the fixationportion comprises a mesh.
 20. Visual prosthesis apparatus comprising adevice implantable in the eye of a patient, one or more conductorsconfigured to extend from the implantable device out of an opening inthe surface of the eye, to a communications interface remote from theeye, and an anchor device according to any one of the preceding claims.21. The apparatus of claim 20, wherein the implantable device comprisesan array of electrodes configured to apply electrical current to retinalcells of the eye.
 22. The apparatus of claim 20 or 21, wherein thecommunications interface comprises a wireless transmitter/receiver, oran electrical connector, for communication between the implantabledevice and an electrical component.
 23. The apparatus of claim 20, 21 or22, wherein the conductors travel through a transition portion betweenthe implantable device and the anchor device.
 24. The apparatus of claim23, wherein the transition portion is flexible.
 25. The apparatus ofclaim 24, wherein the transition portion comprises a lead section havinga diameter that does not increase from the anchor device to theimplantable device.
 26. The apparatus of claim 25, wherein thetransition portion comprises a lead section having a diameter thatdecreases from the anchor device to the implantable device.
 27. Theapparatus of any one of claims 20 to 24 comprising a lead adapted toconnect the device implantable in an eye to the communicationsinterface, the communications interface being external to the eye, theone or more conductors extending through the lead.
 28. The apparatus ofclaim 27, wherein the lead comprises: a reinforcement device, thereinforcement device having a first end and a second end and beingelongated between the first end and the second end, the reinforcementdevice being positionable at or adjacent an orbital bone; a first leadsection connected to the first end of the reinforcement device; a secondlead section connected the second end of the reinforcement device;wherein the reinforcement device has a greater outer diameter than thefirst and second lead sections.
 29. The apparatus of claim 27 or 28,wherein the lead is configured to locate in a notch formed in theorbital bone.
 30. The apparatus of claim 27, 28 or 29, wherein the leadis pre-shaped to substantially follow an outer surface of the orbitalbone at the lateral orbital rim adjacent the eye.
 31. A lead forconnecting a device implantable in an eye to a communications interfaceexternal to the eye, the lead comprising: a reinforcement device, thereinforcement device having a first end and a second end and beingelongated between the first end and the second end, the reinforcementdevice being positionable at or adjacent an orbital bone; a first leadsection connected to the first end of the reinforcement device; a secondlead section connected the second end of the reinforcement device; andone or more conductors, wherein the conductors are connectable to theimplantable device and are configured to extend from the implantabledevice, through the first lead section, the reinforcement device and thesecond lead section, to the communications interface, wherein thereinforcement device has a greater outer diameter than the first andsecond lead sections.
 32. The lead of claim 31, wherein thereinforcement device comprises a bend region for extending around theorbital bone.
 33. The lead of claim 32, wherein the reinforcement devicecomprises a first reinforcement section extending from the bend regionto the first end, and a second reinforcement section extending from thebend region to the second end.
 34. The lead of claim 33, wherein thefirst reinforcement section has a length of between 0.5 and 3 cm and thesecond reinforcement section has a length of ° between 0.2 and 2 cm. 35.The lead of claim 33 or 34, wherein the bend region maintains an anglebetween the first and second reinforcement sections of between about 45°and 90°.
 36. The lead of any one of claims 31 to 35, wherein thediameter of the reinforcement device is between about 1 mm and 5 mm andthe diameter of the first and second sections is between about 0.5 mmand 3 mm.
 37. The lead of any one of claims 31 to 36, comprising atapered transition region between one or both of the first and secondsections and the reinforcement device.
 38. The lead of any one of claims31 to 37 wherein the reinforcement device is configured to locate in anotch formed in the orbital bone.
 39. Visual prosthesis apparatusincluding a device implantable in an eye, a communications interface,and a lead extending between the implantable device and thecommunications interface, wherein the lead is pre-shaped tosubstantially follow an outer surface of the orbital bone at the lateralorbital rim adjacent the eye.
 40. A method for securing a reinforcementdevice according to any one of claims 31 to 39 to an orbital bone,comprising: forming a notch in the orbital bone, wherein the notchcomprises a recessed groove configured tdd receive the reinforcementdevice and an access opening through which the reinforcement device islocatable in the recessed groove, wherein the access opening is narrowerthan the recessed groove.
 41. The method of claim 40, comprisingpress-fitting the reinforcement device through the access opening intothe recessed groove.
 42. Positioning apparatus for positioningcomponents of electrical apparatus, the electrical apparatus including adevice implantable at a target portion of a patient's body, acommunications interface, and a lead extending between the implantabledevice and the communications interface, the positioning apparatuscomprising: an elongate element having a proximal end and a distal end,the distal end being insertable through a first incision in a surface ofa patient, and movable under tissue towards the target position, and ahandle portion releasably attachable to a proximal end region of theelongate element; wherein the elongate element has a first recess at thedistal end adapted to receive the implantable device and a channelextending proximally from the first recess adapted to receive the lead,and wherein the handle includes a second recess adapted to receive thecommunications interface.
 43. The positioning apparatus of claim 42,wherein the electrical apparatus is a visual prosthesis, the visualprosthesis including the implantable device, the device beingimplantable in an eye, the communications interface, and the leadextending between the implantable device and the communicationsinterface, and wherein: the distal end of the elongate element isinsertable through the first incision in a skin surface of a patient,and movable under tissue towards a patient's eye.
 44. The apparatus ofclaim 43, wherein the distal end of the elongate element is movableunder the tissue through a second incision in a skin surface of thepatient, the second skin incision being located at or adjacent thelateral orbital margin of the eye socket surrounding the eye.
 45. Theapparatus of claim 42, wherein the electrical apparatus is adapted tolimit or prevent onset of epileptic seizures, and/or to monitor bodyparameters associated with epileptic seizures
 46. The apparatus of anyone of claims 42 to 45, wherein the elongate element comprises a head atthe distal end that includes the first recess and an arm extendingproximally from the head, the arm including the channel, wherein thechannel has an opening at its distal end that opens into the firstrecess.
 47. The apparatus of claim 46, comprising a releasable lid forcovering the first recess.
 48. The apparatus of any one of claims 42 to47, wherein the handle comprises first and second portions configured toreleasably clamp together from opposite sides of the arm, fixing theposition of the handle relative to the arm.
 49. The apparatus of claim48 wherein the clamping secures the communications interface in thesecond recess.
 50. The apparatus of any one of claims 42 to 49, whereinthe elongate element is bent to follow contours of a human skull. 51.The apparatus of any one of claims 42 to 49, wherein the elongateelement is substantially straight.
 52. A method of positioningcomponents of electrical apparatus, the electrical apparatus including adevice implantable at a target position in a patient's body, acommunications interface, and a lead extending between the implantabledevice and the communications interface, the method comprising:inserting a distal end of an elongate element through a first incisionremote from the target position, wherein the elongate element has: afirst recess at the distal end, the implantable device being at leastpartially located in the first recess, and a lead channel extendingproximally from the first recess, the lead being at least partiallylocated in the lead channel, and wherein a handle is releasably attachedto a proximal end of the elongate element, the handle including a secondrecess, the communications interface being at least partially located inthe second recess; moving the distal end of the elongate device undertissue towards the target position; pushing the distal end of theelongate device out of a second incision adjacent the target position;removing the implantable device from the first recess; releasing thehandle portion from attachment with the elongate element; removing thecommunications interface from the second recess; and pulling theelongate element out of the second incision.
 53. The method of claim 52,wherein the electrical apparatus is a visual prosthesis, the visualprosthesis including the implantable device, the device beingimplantable in a patient's eye, the communications interface, and thelead extending between the implantable device and the communicationsinterface, wherein: the first incision is a first skin incision remotefrom the patient's eye and the second incision is a second skin incisionadjacent the patient's eye; the distal end of the elongate device ismoved under tissue towards the patient's eye; and the distal end of theelongate device is pushed out of the second skin incision adjacent thepatient's eye.
 54. The method of claim 53, wherein the first incision isin the posterior temporalis muscle and the second incision is at thelateral orbital margin.
 55. The method of claim 52, wherein theelectrical apparatus is adapted to limit or prevent onset of epilepticseizures, and/or to monitor body parameters associated with epilepticseizures.
 56. The method of any one of claims 52 to 55, wherein theelongate element comprises a head at the distal end that includes thefirst recess and an arm extending proximally from the head, the armincluding the channel, wherein the channel has an opening at its distalend that opens into the first recess.
 57. The method of any one ofclaims 52 to 56, comprising a lid for covering the first recess, whereinthe lid is released to remove the implantable device from the firstrecess.
 58. The method of any one of claims 52 to 57, wherein the handlecomprises first and second portions configured to releasably clamptogether from opposite sides of the arm, fixing the position of thehandle relative to the arm, wherein clamping of the first and secondportions is released to remove the communications interface from thesecond recess.
 59. The method of any one of claims 52 to 58 comprising,prior to insertion of the distal end of the elongate element through thefirst incision, forming a pocket between the first and second incisionsusing a dummy element.
 60. The method of claim 59, wherein the dummyelement has a similar or identical profile to the elongate element. 61.The method of any one of claims 52 to 60, wherein the elongate elementis bent to follow contours of a human skull.
 62. The method of any oneof claims 52 to 60, wherein the elongate element is substantiallystraight.